1. Field of the Invention
The invention relates to a terminal fitting that prevents fine sliding abrasion.
2. Detailed Description of the Related Art
Terminal fittings often are used in a high vibration environment. The vibration may cause the contact portions of the terminal fittings to undergo a fine sliding abrasion, and hence electrical resistance at the contact portions may increase. A terminal fitting designed to prevent fine sliding abrasion is disclosed in WO 98/29924 and also is identified by the numeral 1 in FIG. 6 herein. The terminal fitting 1 has a rectangular tubular connecting portion 6 for receiving a mating male tab 9. The connecting portion 6 has a side wall 2 that is cut to form a resilient supporting piece 3. The connecting portion 6 also has a ceiling surface that is formed to define a receiving portion 4 that is coupled to the resilient supporting piece 3. A resilient contact piece 5 extends from the receiving portion 4 and cooperates with the receiving portion 4 to squeeze the male tab 9. The male tab 9 may undergo a fine vibration longitudinally along its inserting direction into the connecting portion 6. However, the resilient supporting piece 3 deforms and permits the resilient contact piece 5 and the receiving portion 4 to follow the vibration along the longitudinal direction. Thus, fine sliding abrasion at the contact portions of the two terminals 1, 9 is alleviated.
The resilient supporting piece 3 extends up in FIG. 6 and then projects forward from the plane of FIG. 6 to couple with the receiving portion 4. Thus, the resilient contact piece 5 does not follow the male tab 9 satisfactorily.
The present invention was developed in view of the above situation, an object thereof is to provide a terminal fitting having a resilient contact piece which can satisfactorily follow up a male tab in contact therewith.
The invention is directed to a terminal fitting that comprises a connecting portion into which a mating male terminal is insertable. A resilient contact piece is provided in the connecting portion and extends substantially in a longitudinal direction. The resilient contact piece is resiliently deformable in a direction that intersects the longitudinal direction and includes a contact that can be brought electrically into contact with the mating male terminal. The resilient contact piece is displaceable along the longitudinal direction or the insertion direction of the male tab. Accordingly, the resilient contact piece can easily follow a displacement of the male tab along the longitudinal or insertion direction.
A resilient supporting piece couples a lateral edge of the resilient contact piece to a side wall of the connecting portion, thereby enabling longitudinal displacement of the resilient contact piece with the resilient supporting piece as a center.
The resilient supporting piece preferably is separated from the side wall by a pair of slits. Hence, the resilient supporting piece projects sideways along a direction that intersects the longitudinal direction.
Additionally, the resilient supporting piece preferably is covered at least partly by an outer side wall arranged outward of the side wall.
The terminal fitting may further comprise an auxiliary spring between the contact and a portion of the resilient contact piece coupled to the side wall of the connecting portion, preferably the resilient supporting piece. The auxiliary spring preferably is resiliently displaceable along the longitudinal direction.
The male terminal engages the contact and deforms the resilient contact piece. The resilient contact piece and the auxiliary spring are displaced longitudinally with the resilient supporting piece as a center if the connected male terminal vibrates longitudinally. Thus, the resilient contact piece vibrates longitudinally as the male terminal vibrates and the contacts of the two terminals do not undergo a fine sliding abrasion.
The auxiliary spring is at an intermediate position of the resilient contact piece and extends longitudinally along the resiliently displacing direction. Thus the auxiliary spring is displaced smoothly, thereby improving its capability of following up the male terminal.
The auxiliary spring is backward from the contact with respect to an inserting direction of the mating male terminal. Thus, the mating male terminal can be inserted forcibly into the connecting portion without interfering with the auxiliary spring, and the auxiliary spring can display its spring force reliably.
The auxiliary spring preferably comprises at least one curve. Intervals defined by the respective curves can be narrowed and widened to allow the resilient contact piece to be displaced along the longitudinal direction.
The curve preferably is more inward than a corresponding lateral wall of the connecting portion and/or is more outward than the contact portion.
A lateral wall of the connecting portion may have a hole that partly overlaps the auxiliary spring, so that the auxiliary spring is exposed to outside.
The resilient contact piece preferably comprises a straight portion extending substantially parallel to the longitudinal direction. Thus, the auxiliary spring extends parallel to the longitudinal direction, and is displaced smoothly, as compared, for example, to a case where the auxiliary spring extends oblique to the longitudinal direction.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.